What other types of animals lived at the time of the dinosaurs?
During the Triassic Period, a lot of plants and animals existed along with the dinosaurs. There were all types of animals (except birds)—crocodiles, turtles, lizard relatives, giant amphibians, and the first mammals. In the oceans, there were many types of reptiles, sharks, and fish, including ichthyosaurs, predatory sea reptiles that ate shellfish, fish, and other marine reptiles. They looked similar to, and probably had some of the same habits of modern dolphins, whales, and sharks. Some animals were closely related to the land-dwelling dinosaurs, like the flying pterosaurs. These creatures were all different sizes—some skimmed the surface of the water while others flew like birds. At the beginning of the Jurassic period, dinosaurs began to dominate the land. But there were still plenty of salamanders, frogs, turtles, lizards, small mammals, and ancient crocodiles, the crocodilians. During the Cretaceous period, many crocodiles became massive, including the Deinosuchus, a large land creature that reached 50 feet (15 meters) in length. By this time there were also snakes, birds, winged insects, and mammals.